Magnetic separation of iron ore.



No. 812,172. FATENTED' FEB. s, 1906. G. GBDNDAL. MAGNETIC SEPARATION OF IRON ORE.

APPLIOATION FILED DEC. 3. 1904.

INVENTOR WITNESSES ATTORNEYS .4 a a. s

s 'l eSS and thegangue; and'at the same time to se aratethe latter. two from "eachother; For I purpose the 'materiai designing aojseparately, and the richer layer of the current GUSTAF GRONDAL, OF

PATENT OFFICE.

DJURSHOLM, SWEDEN MAGNETIC .sEPAR T oN 0'? IRON one,

Specification of Letters Patent.

Patented Feh. e, 1906.

Origipal application filed NovembardZ, 190a, seen mi. 180,904; Divided and this application an December a, 1904. Serial w a y Ko.236,894.

invented certainnew and useful Improvemerits in Magnetic Separation of Iron Ore,

(for whichI have appliedfor a patent in Norwa April.- ,'1903, Ng. 16,254,) of which the fol owingisaspecificatiohfi i i6. Thepresent: 1nv tion refers to a method {of .efiecting ,by means ofa n agnetic separation of pulverized iron ore a practically complea; "separationof. the most magnetic par- 'ticles,1 the--particles of 'pure iron ore from thev pulverized to the necessary small size is suspended in water and led horizontally, or 2o nearly so, through a magnetic field in the roximity of but not in contact with the polepiece of' a stationary magnet. By properly the apparatus as to the power of theitrnagnet the distance between the lepiece and the surface of the current wit the {suspended material and by regulating the depth and-rapidity of said current the -magarticlesare attracted and separated Efrem t anon-magnetic particles at some disa tanc'e on the side of the pole-piece andthe est-magnetic articlesthose of pure magv ticliron'ore, or instance-in. passing the; "poIe-piece are lifted up out of the water to-; jgvard the magnet, while the less magnetic 35 particles are not drawn through and out ofthe water, but remain in a layer at and under ,the surface of the water, the said layer being a richer than the layer underneath. The pa r" ticles drawn .out of the water are gathered containing the less magnet c particles is led off separately to be further enriched, if desired.

. In order to gather and lead away the particles drawn toward the magnet, each of the llow drum madeof a magnetically-indi erent material suchias zinc or brass, the said drum being ept rotating in the same direction as the current containin the suspended 5'0 material, The pole-piece is ormed with an edge-lying-behind and near the art-of the .drum past which the currentis le the mantle of the drum being provided with lamels -the pole-pieces.=

of iron inserted into t, which carry the pari ticles along withthem a bit and-then let them loose. Water-jets directed against the drum on-suitable places may, howeveijbe used for removing them whollyt In the accompanying drawings there is shown diagrammatically and as an example only a form of a'pparatusfor carrying out the.

separation. 1

Figure 1 1s an elevation, partlyin section,

along the. line 1- 11m LheFig. -2. Fig. 2 is-a vertical section alongth'ex'line 2 2 of the F l a is an electromagnet. r b b are its pole-.- sjreces, which are .fo'rmedwith a downwardly ected elo ated'edge c. n :11 is afsha passing through the magnet and carrying the-.ldrums'earound the pole.

pieces, resp tively,.and a belt pulloyffnr mtating the'drums. thedrawings the drum.

W'ith thd'aCCSso partsfis omitted at one 01' g isa-vessel' divided into two compartmentsri and k-hy an inclined partition It. Zisa supply-pipe for the suspended material 'entering' into the "compartment 1', and. m is a dischargepip'e provided with a cock from the compartment k.

n is an overflow-discharge located a little lower than the top of the artition h. i

0 indicates an adjustab e late for varying 1 their' ht of the overfiow-. lscharge. 12 18 a channel leading therefrom.

q is a channel located above the overflowdischarge.

r is awater-pipe provided with perforations toward the drum 0 for washing away the ore particles. 1

The apparatus operates as follows: The vessel g is filled with water, and the drum e is put in rotation. The suspended material is then let on throu hthe pipe Z, and itrises in the chamber 1' an over the top of the partition It. Fromlthis ed 0 the current containended ma rial'flows toward the overflow-discharge n, arid on the'iway the ing the susp se aration is effected by means of thei'powerrul magnet in such a manner that the magnetic .mater'ial is drawli upward toward the surface, of the current already from the he inning,.- and-the mamas material'is 16a to sink,- when tightuh'der the magnet the-mostmagnetic particles are lifted .outof the water'towardthe drum 6, and they fasten on the lattnlwhile the-less magnetic particles flow awayovcr the cverflowfdis edge c of the.

' netic' material at the bottom of the body of char-gen throughthe channel 1) and are gathered for-further tre'a tment The non-metallic material, or 'thegangue winch falls down m the compartment Ir, lsdrawn ofi' throu h the pipe m The particles adhering to the si owlyrotating drum 0 fall'ofi and are washed from 1' the drum and fall down into the channel q, being gathered for furtherrtreatment.

' of susp gole pieces treatsa po The apparatus mayibeairanged' either so removing'thc particles from the latter at another point, and withdrawing the non-mag- ;liquidf l t 2 The}- rocess of separatin Xulvenzcd susPending i l ore in a body of liquid, maintaining the horizontal surface-level of this liquid undera moving surface in proximity to but free from contact with the surface of the liquid b a surface overflow, magnetica 1y lifting the more magnetic particles out of theliquid into a layer on'the said moving surface, gathering the la 'er of particles which, have been lifted out o the water, and withdrawing the nonmagnetic material at the bottom of the bed y of the liquid.

8. The process of separating pulverized ore, consisting in leading astream of liquid carrying the ore horizontally below in proximity to but free from contact with a moving surface, magnetically pulling the most mag-- netic particles of ore up out of the liquid into a layer on said moving surface and at the same' time gathering less magnetic particles of ore in the liquid near its surface and leading the same away and letting the dead ore sinkdown in the liquid and fiow away.

maintaining In testimony whereof I have signed my name to this specification .in the presence of two subscribing witnesses.

' GUSTAF 'GRONDAL. Witnesses:v

' GUSTAF'VJEMI, 1 M. .G. AUs'rRoM. 

